<!DOCTYPE HTML>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <title>运营系统登录页</title>

    <link href="../res/css/logins.css" rel="stylesheet" type="text/css">
    <script type="text/javascript" src="../res/js/jquery..9.1.js"></script>
    <script src="../res/js/loginsyemian.js" tppabs="static/js/verificationNumbers.js"></script>
    <style>
        .J_codeimg{z-index:-1;position:absolute;}
    </style>
    <script>
        $(document).ready(function() {
            //验证码
            createCode();
        });
    </script>
</head>
<body>
<div class="login-box" id="demo">
    <div class="input-content">
        <div class="login_tit">
            <div>
                <i class="tit-bg left"></i>
                Everyday · 运营系统
                <i class="tit-bg right"></i>
            </div>
            <p>Strive&nbsp;&nbsp;&nbsp;&nbsp;Everyday</p>
        </div>
        <p class="p user_icon">
            <input type="text" placeholder="账号" autocomplete="off" class="login_txtbx">
        </p>
        <p class="p pwd_icon">
            <input type="text" placeholder="密码" autocomplete="off" class="login_txtbx">
        </p>
        <div class="p val_icon">
            <div class="checkcode">
                <input type="text" id="J_codetext" placeholder="验证码" autocomplete="off" maxlength="4" class="login_txtbx">
                <canvas class="J_codeimg" id="myCanvas" onclick="createCode()" onselectstart="return false">对不起，您的浏览器不支持canvas，请下载最新版浏览器!</canvas>
            </div>
            <a class="ver_btn" onclick="createCode();" onselectstart="return false">看不清，换一张</a>
        </div>
        <div class="signup">
            <a class="gv" href="#" onclick="validate()">登&nbsp;&nbsp;录</a>
            <a class="gv" href="#">清&nbsp;&nbsp;空</a>
        </div>
    </div>
    <div class="canvaszz"> </div>
    <canvas id="canvas"></canvas>
</div>
<script>
    //宇宙特效
    "use strict";
    var canvas = document.getElementById('canvas'),
        ctx = canvas.getContext('2d'),
        w = canvas.width = window.innerWidth,
        h = canvas.height = window.innerHeight,

        hue = 217,
        stars = [],
        count = 0,
        maxStars = 2500;//星星数量

    var canvas2 = document.createElement('canvas'),
        ctx2 = canvas2.getContext('2d');
    canvas2.width = 100;
    canvas2.height = 100;
    var half = canvas2.width / 2,
        gradient2 = ctx2.createRadialGradient(half, half, 0, half, half, half);
    gradient2.addColorStop(0.025, '#CCC');
    gradient2.addColorStop(0.1, 'hsl(' + hue + ', 61%, 33%)');
    gradient2.addColorStop(0.25, 'hsl(' + hue + ', 64%, 6%)');
    gradient2.addColorStop(1, 'transparent');

    ctx2.fillStyle = gradient2;
    ctx2.beginPath();
    ctx2.arc(half, half, half, 0, Math.PI * 2);
    ctx2.fill();

    // End cache

    function random(min, max) {
        if (arguments.length < 2) {
            max = min;
            min = 0;
        }

        if (min > max) {
            var hold = max;
            max = min;
            min = hold;
        }

        return Math.floor(Math.random() * (max - min + 1)) + min;
    }

    function maxOrbit(x, y) {
        var max = Math.max(x, y),
            diameter = Math.round(Math.sqrt(max * max + max * max));
        return diameter / 2;
        //星星移动范围，值越大范围越小，
    }

    var Star = function() {

        this.orbitRadius = random(maxOrbit(w, h));
        this.radius = random(60, this.orbitRadius) / 18;
        //星星大小
        this.orbitX = w / 2;
        this.orbitY = h / 2;
        this.timePassed = random(0, maxStars);
        this.speed = random(this.orbitRadius) / 500000;
        //星星移动速度
        this.alpha = random(2, 10) / 10;

        count++;
        stars[count] = this;
    }

    Star.prototype.draw = function() {
        var x = Math.sin(this.timePassed) * this.orbitRadius + this.orbitX,
            y = Math.cos(this.timePassed) * this.orbitRadius + this.orbitY,
            twinkle = random(10);

        if (twinkle === 1 && this.alpha > 0) {
            this.alpha -= 0.05;
        } else if (twinkle === 2 && this.alpha < 1) {
            this.alpha += 0.05;
        }

        ctx.globalAlpha = this.alpha;
        ctx.drawImage(canvas2, x - this.radius / 2, y - this.radius / 2, this.radius, this.radius);
        this.timePassed += this.speed;
    }

    for (var i = 0; i < maxStars; i++) {
        new Star();
    }

    function animation() {
        ctx.globalCompositeOperation = 'source-over';
        ctx.globalAlpha = 0.5; //尾巴
        ctx.fillStyle = 'hsla(' + hue + ', 64%, 6%, 2)';
        ctx.fillRect(0, 0, w, h)

        ctx.globalCompositeOperation = 'lighter';
        for (var i = 1, l = stars.length; i < l; i++) {
            stars[i].draw();
        };

        window.requestAnimationFrame(animation);
    }

    animation();
</script>

</body>
</html>